JPH09254831A - Turnover preventing device for articulated type dump truck rear body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent rear body of an articulated type dump truck from turning over when a load is dumped at an inclined ground. SOLUTION: A brake caliper 21 is fixed to a front body frame 6 and a brake disc 20 is fixed to a connecting member 11 installed on the front body frame 6 in the manner of allowing rotational movement in X-X axial rotation. The connecting member 11 has a rear body frame 77 installed thereon in the manner of allowing rotational movement in perpendicular axial Y-Y rotation. With a brake piece 22 provided in the interior of the brake caliper 21, it is oscillatory fixed by having the brake 'on' when a load is being dumped and the turnover of the rear body is prevented by adding the weight of the front body to the rear body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear body fall prevention device for an articulated dump truck equipped with an oscillation device.

[0002]

2. Description of the Related Art An articulated dump truck has a vertical axis for articulation at a connecting portion between a front body frame and a rear body frame, and a horizontal axis in the front-rear direction. Since the front and rear wheels can be turned on, that is, oscillation can be performed, the grounding performance of the front and rear wheels can be improved and the running stability of the vehicle body can be improved. The details of the articulated dump truck will be described below.

FIG. 1 is a side view of an articulated dump truck, and FIG. 2 is a plan view thereof. A front vehicle body 1 having front wheels 2 and a rear vehicle body 3 having rear wheels 4 are connected by a connecting device 10. The rear vehicle body 2 is equipped with a vessel 5 for loading earth and sand or the like, and at the time of earth unloading, the vessel 5 is dumped rearward by a dump cylinder (not shown) as shown by a thin double-dashed line for earth unloading.

FIG. 3 is a perspective view of the connecting device 10 which is the portion P of FIG. One end of the connecting member 11 is attached to the front vehicle body 1 so as to be rotatable about the horizontal axis X-X in the front-rear direction, that is, oscillating, as indicated by the arrow.
A rear body frame 7 is attached to the other end of 1 so as to be rotatable around a vertical axis Y-Y.

When turning while traveling, as shown in FIG. 2, the front vehicle body 1 is rotated rightward or leftward around a vertical axis YY (see FIG. 3) as indicated by a thin two-dot chain line. , Is supposed to turn. Since the front vehicle body 1 and the rear vehicle body 3 rotate about the horizontal axis XX (see FIG. 3) and can oscillate, the load on the tire is evenly applied during turning, and the outer wheels are In order to prevent it from sinking, it is possible to run stably even on a harsh upper limit of soft ground, prevent the vehicle from tipping over, and extend the life of the tire.

However, when dumping the vessel at the time of dumping, the center of gravity becomes high, the terrain is inclined in the left-right direction, or the rear body can oscillate when one side of the rear wheel is on soft ground. Therefore, there is a problem that it is easy to fall in the lateral direction.

As an articulated vehicle whose rear body can oscillate, there is a wheel type front loader in addition to a dump truck, which has conventionally suppressed the rear body oscillation and is stable during running. There are attempts to improve. As an example, Shokai Sho 6
0-139678, and another example is the one proposed in JP-B-64-389.

[0008] That is, Japanese Utility Model Laid-Open No. 60-139678
A lever is fixedly mounted on a swing shaft for oscillation that is rotatably provided in the rear center of the front body frame, and the lever and the front body frame are connected by a swing control cylinder. Then, the movement of the rocking control cylinder is fixed by a signal from a pressure switch that operates at a hydraulic pressure slightly lower than the hydraulic pressure of the working machine in which the rear body floats. As a result, the left and right swings of the rear vehicle body in a lifted state are prevented to give the operator a sense of security and the entire weight of the rear vehicle body is effectively used as the force of the working machine.

In Japanese Utility Model Publication No. 64-389, a lever is fixedly mounted on a swing shaft for oscillation that is rotatably provided at the center of the rear part of a front body frame, and the lever and the front body are shock absorbers. Are connected by.
This prevents the front vehicle body from abruptly inclining at the time of work or high-speed turning so as not to give the operator a sensual anxiety.

[0010]

However, all of the above proposals are related to the wheel type front loader, and the purpose thereof is also different, and they are not suitable for being directly applied to the articulated type dump truck. The present invention has been made in view of the above problems, and prevents the rear body of the articulated dump truck from overturning even when dumping and discharging soil on a sloping ground or soft ground. The purpose is to provide a device.

[0011]

In order to achieve the above-mentioned object, in a rear body fall prevention device for an articulated dump truck according to the present invention, a connecting portion between a front body frame and a rear body frame is provided with: An articulated dump truck equipped with an oscillation device rotatable about a horizontal axis in the front-rear direction is provided with an oscillation fixing means including a brake disc and a brake caliper for braking the brake disc.

The oscillation fixing means comprises a brake hydraulic pressure source for operating the brake caliper, and a switching valve for performing ON-OFF control of the brake caliper.

A switching signal generating means for instructing ON-OFF control of the switching valve is provided.

[0014]

With the above-mentioned structure, the oscillation fixing means provided at the connecting portion between the front body frame and the rear body frame is turned on and off at a predetermined time by the signal from the switching signal generating means. By fixing the oscillation, the weight of the front vehicle body can be added to the rear vehicle body, and the rear vehicle body can be prevented from falling.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an articulated dump truck rear body fall prevention device according to the present invention will now be described in detail with reference to the drawings.

FIG. 4 is a side sectional view of a coupling device 10 equipped with a rear body fall prevention device for an articulated dump truck according to the present invention. An outer race 13 of a ball bearing 12 is fastened to a front body frame 6 by bolts 14 in parallel with a horizontal axis X-X in the front-rear direction, and one end of a connecting member 11 is attached to an inner race 15 by a bolt 16. It is fastened. Further, the rear body frame 7 is attached to the other end of the connecting member 11 via a pair of tapered roller bearings 17 and 17 by articulated hinge pins 18 and 18 arranged perpendicularly to the horizontal axis XX. There is. Therefore, the connecting member 11 is rotatable about the horizontal axis XX,
That is, oscillation is possible, and the rear body frame is rotatable about the vertical axis Y-Y.

A brake disc 20 is fastened together with a bolt 16 between the inner race 15 of the ball bearing 12 and the connecting member 11, a brake caliper 21 is provided on the front body frame 6, and an outer race 13 of the ball bearing 12 is provided. Along with it, it is fastened by bolts 14. The brake caliper 21 has a pair of brake pieces 22 and 22 so that the brake disc 20 can be held and braked.

The brake piece 22 and a hydraulic pump 23 for operating the brake piece 22 are connected by a circuit 27 via an electromagnetic switching valve 24 for performing brake ON-OFF control, and the electromagnetic switching valve 24 is connected to a limit switch 25. ing. The limit switch 25 may be a pressure switch. ON / OFF of the limit switch 25 causes the solenoid switching valve 24
Is switched to the (a) position or the (b) position and the brake is turned on or off. When the dump cylinder (not shown) reaches a predetermined stroke, the limit switch 25 receives a signal from a stroke detector (not shown) of the dump cylinder to turn on the brake, and the left and right tilt angles of the front vehicle body 1 reach a predetermined angle. Then, the brake is set to 0FF in response to a signal from a front vehicle body left / right tilt angle detector (not shown). Reference numeral 26 is a pressure regulating valve.

Next, the operation will be described. As shown by the thin double-dashed line in FIG. 1, when the vessel 5 loaded with earth and sand is dumped for dumping, the ground is sloping in the lateral direction, or the ground on either side of the rear wheel 4 is left or right. Is weak, the rear vehicle body 3 leans in the left-right direction.
At this time, the center of gravity of the rear vehicle body 3 is high, and when the lateral inclination angle of the rear vehicle body 3 reaches or exceeds a predetermined angle,
The connecting member 11 part oscillates about the horizontal axis XX and falls. In order to prevent this, as described above, when the dump cylinder reaches a predetermined stroke (when the dump angle of the vessel 5 reaches a predetermined angle), the limit switch 25 receives the signal, and the electromagnetic switching valve 24 (a). ) Position and turn on the brake of the coupling device 10. As a result, the weight of the front vehicle body 1 is added to the weight of the rear vehicle body 3, so that the rear vehicle body 3 is prevented from falling. The ratio of the weight of the front vehicle body 1 to the weight of the rear vehicle body 3 is that of the rear vehicle bodies 6 to 7 with respect to that of the front vehicle bodies 3 to 4.

If the fall cannot be prevented even when the brake is turned on, the front vehicle body 1 will fall at the same time, which is dangerous. Therefore, as described above, when the left-right inclination angle of the front vehicle body 1 reaches a predetermined angle, the limit switch 25 receives the signal, sets the electromagnetic switching valve 24 to the (b) position, and turns the brake OFF to turn the front vehicle body 1 off. It is possible to prevent falls and save lives. ON of limit switch 25-
The OFF control signal is not limited to the stroke of the dump cylinder, but also the inclination of the vessel 5, the hydraulic pressure of the dump cylinder,
Alternatively, the movement of the dump operation lever may be detected and transmitted.

[0021]

The articulated dump truck rear vehicle body overturn prevention device according to the present invention has the above-described structure. Therefore, when dumping and discharging soil, the articulated dump truck rear vehicle vehicle overturn prevention device is provided in the connecting device between the front vehicle body and the rear vehicle body. Use the oscillation fixing means to fix the rotation around the horizontal axis, and add the weight of the front car body to the rear car body to tip over even on a laterally sloping ground or one side of the rear wheel on soft ground. Can be prevented. In addition, when it is impossible to prevent the vehicle from toppling over when dumped with the oscillation fixed, there is a risk that the front vehicle body may also overturn. It is possible to secure.

[Brief description of drawings]

FIG. 1 is a side view of an articulated dump truck.

FIG. 2 is a plan view of FIG.

3 is a perspective view of the coupling device in FIG. 1. FIG.

FIG. 4 is a detailed side view showing an embodiment of a connecting portion provided with a rear vehicle body overturn prevention device according to the present invention.

[Explanation of symbols]

 1 Front Car Body 3 Rear Car Body 6 Front Car Body Frame 7 Rear Car Body Frame 10 Coupling Device 11 Coupling Member 12 Ball Bearing 17 Tapered Roller Bearing 18 Articulated Hinge Pin 20 Brake Disc 21 Brake Caliper 22 Brake Piece 23 Hydraulic Pump 24 Electromagnetic Switching Valve 25 Limit switch

Front page continuation (72) Inventor Takahisa Fujimoto 2-3-6 Akasaka, Minato-ku, Tokyo Komatsu Ltd. Head Office

Claims (3)

[Claims] 1. A brake disc and a brake disc in an articulated dump truck, comprising an oscillation device rotatable around a horizontal axis in the front-rear direction at a connecting portion between a front body frame and a rear body frame. A rear vehicle body fall prevention device for an articulated dump truck, comprising an oscillation fixing means composed of a brake caliper for braking the vehicle. 2. The articulated dump truck rear vehicle body overturn prevention device according to claim 1, wherein the oscillation fixing means is a brake hydraulic pressure source for operating a brake caliper, and an ON-OF of the brake caliper.
A rear body fall prevention device for an articulated dump truck, which is provided with a switching valve for performing F control. 3. The articulated dump truck rear vehicle body overturn prevention device according to claim 2, further comprising switching signal generation means for instructing ON-OFF control of the switching valve. Rear body fall prevention device for trucks.